According to a new study on ADHD, in the U.S. more cases are being diagnosed at a younger age and their number is rising rapidly. The federal report indicates that a full third of U.S. children who are displaying attention deficit hyperactivity disorder (ADHD) are being diagnosed before they reach the age of six.

The authors of the report point out that these alarming numbers are registered despite the existence of very few valid tests that can diagnose ADHD in children so young. Among the experts, there is actually some debate about whether the study suggests an over-diagnosis of the condition. ADHD symptoms include impulsive behavior, hyperactivity and inattention. All of these compartments can negatively impact a child's ability to learn and perform well in school.

According to Joel Nigg, director of the division of psychology at Oregon Health & Science University in Portland, the instrumentation and guidelines for diagnosing preschool children are still weak. The ADHD condition itself, since is developmental, it Is expected to be normal among preschool children.

Nigg added that many of the diagnoses of ADHD in young children may be valid. The expert from Oregon Health and Science University in Portland was not involved in the study, which was reported by the U.S. Centers for Disease Control and Prevention (CDA). For their research, the scientists at the U.S. National Center on Birth Defects and Developmental Disabilities organized a survey in which they interviewed nearly 3,000 parents of children diagnosed with ADHD.

The findings of the survey show that more than a third of the children had been diagnosed before age six and more than a half had been diagnosed before age seven. In the second group, in three out of four cases it was a family member or a parent who first became concerned about the child's behavior and thought they have identified signs of ADHD.

According to study lead author Susanna Visser, lead author of the study, the findings suggest that in the vast majority of cases a relative of the child was the first to express concern about their performance or behavior.

Visser suggests that with the guidelines released in the year 2013 by the American Academy of Pediatrics this may have helped raise awareness and this can explain those new diagnoses.